“Super bacteria” cleaning up after oil spills

Researchers in Trondheim have achieved surprising results by exploiting nature’s own ability to clean up after oil spills.

We all know that marine bacteria can assist in cleaning up after oil spills. What is surprising is that given the right kind of encouragement, they can be even more effective.

“We know that oil spills happen – and that they will happen again”, says Roman Netzer, a researcher and biologist at SINTEF. “We also know that this can have a major negative impact on the natural environment. This is why we’ve been studying a series of chemical and biological analytical techniques to assess the levels of seriousness of oil spills. We also wanted to find out whether so-called bioremediation represents an effective approach to cleaning up after such accidents”, he explains.

Bioremediation is nature’s way of cleaning up. Plants, bacterial decomposers or enzymes are used to remove contaminants and restore the balance of nature in the wake of pollution incidents.

Tool box

When we clean up after an oil spill of a given size, such as along our shorelines, we start by applying mechanical methods using spades and brooms, combined with chemicals. However, we shouldn’t deceive ourselves, even when the worst of the spill has been cleared away. The surface usually conceals oil buried deeper in the sediment.

“It is here that biological, or bioremediation, methods, come into their own”, says Netzer. “This approach can make cleaning up operations even more thorough, and cost-effective. We wanted to find out what works – and how. And not least to gather data that can be used to support decision-making processes in situations where nature needs that little extra help” he explains.

The "tool box":

The "tool box" is intended primarily for the analysis of bioremediation processes along shorelines in the wake of oil pollution incidents. It will provide decision-makers with vital information as to whether this type of clean-up approach is necessary, recommendations as to the method which should be applied, and a measure of whether the natural environmental balance has been restored following the oil spill. However, it will also be possible to apply this approach to study remediation processes linked to other types of pollution such as that caused by heavy metals or chemicals in other settings such as landfill sites, forestry or industrial facilities.

The chemical analytical equipment used in this project is capable of analysing thousands of oil components. Researchers will apply DNA sequencing technologies to identify the hundreds of different bacteria present in each sediment sample. However, not all information is equally relevant. In order to process the vast amounts of data involved, and extract only what is relevant, the researchers are using advanced statistical methods such as multivariate and principal component analysis to help them arrive at their key conclusions.

So the researchers set up a number of experiments in the marine laboratory. Their aim was to look into how the microscopic residents of the oceans, such as bacteria and other microbes, can assist us in cleaning up pollutants, and whether they are capable of restoring the natural balance afterwards. And not least, to determine the limiting factors involved in this process. It was only after they had failed to achieve any significant response from their initial experiments, causing them to change the experimental parameters, that their sensational results emerged.

When oil-spill sinks down in the sand at a beach, its not easy to see for us humans. But, the bactera does. It’s actually having oil for dinner – if they get some additional “help”. Photo: Svein Ramstad.

Imitating nature along the shoreline

Here at Brattørkaia in Trondheim, researchers have assembled a comprehensive “oil library” which they use in this type of research. The properties of the oils have been accurately measured and recorded, and this enabled the researchers to select the perfect oil for their experiment.

“The oil we chose is produced in large volumes on the Norwegian shelf, and is thus ideal for simulating a realistic scenario involving the accumulation of oil on a Norwegian shoreline”, explains Netzer. “We then tried to simulate what happens in nature when oil becomes stranded”, he says.

Sixteen tanks were filled with sediments, together with naturally-occurring bacterial flora, oil and seawater. The researchers also simulated the action of the tides by replacing the seawater and thus ensuring that there was an adequate supply of oxygen and nutrients. What then happened in the tanks was carefully recorded. But after a month of observations, only minor amounts of contaminants had been removed.

Biological analyses the most sensitive

Chemical and biological analyses carried out afterwards produced approximately the same results.

“However, we noted that the biological approaches, which analyse the concentrations of bacteria, their DNA, and oxygen consumption, were very sensitive and provided us with a great deal of information. Chemical approaches have to be very advanced in order to achieve the same detection thresholds” says Netzer.

“Even the results of the bacterial experiments were obviously disappointing”, he explains. “But the biological results indicated that we were on the right track, and this gave us the idea to give nature a helping hand. We already knew that the bacteria would reproduce – and thus be more effective in their work – if they were provided with additional nutrients. In nature, bacteria flourish best in the presence of high concentrations of phosphates and nitrogen”, says Netzer.

The problem is that the natural concentrations of these substances are insufficient”, he says. So the researchers decided to give them a little supplement.

They also increased the water temperature, reduced the oxygen concentration and extended the duration of the experiment. The tidal regime was also adjusted, so that now there was a 12-hour interval (instead of the previous 3) between the introduction of new water to the tanks.

And this produced results! After one month, the researchers got their clear and unambiguous answers.

The microbial decomposition:

The microbial decomposition of oil along shorelines is influenced by many physical, chemical and biological factors. Parameters such as temperature, access to nutrients, oxygen concentration, the microbial community in question and, not least, the chemical composition of the oil, all influence the process. Oil is composed of a multitude of different components. While some of these are relatively easy for microorganisms to break down, others are more difficult. The composition of the oil is thus a key factor in assessing its potential decomposition by biological processes. SINTEF has been working for several decades to determine the chemical composition and physical properties of the majority of oils encountered on the Norwegian shelf. This database is a potential foundation for a variety of studies contributing to improve emergency preparedness linked to individual fields. This "oil library" is quite unique, and of major significance in the field of oil research.

Analyses revealed that the extra nutrients had enabled the bacteria to work more effectively in breaking down the oil. At the same time, the increase in temperature, reduced oxygen concentration and adjustment of the tidal cycle produced no significant effect.

“We think that the data obtained from these experiments will be of considerable importance to the oil companies – not least because they are now expanding their activities into environmentally-sensitive areas in and around the Barents Sea”, says Netzer. He now envisages the introduction of a new weapon in the battle to clean up after oil spills.

“We believe that in time we will be able to make capsules which can attach themselves to rocks along the shoreline. These will provide the bacteria with ideal growing conditions by releasing nutrients as and when needed”, says Netzer.

Researchers may have found the smallest life forms on Earth. The bacteria they found are much smaller than scientists thought possible.

MORE NORWEGIAN SCITECH NEWS

LOADING CONTENT

Privacy Policy

The Privacy Statement is about how this website collects and uses visitor information. The statement contains information that you are entitled to when collecting information from our website, and general information about how we treat personal data.The legal owner of the website is the processing officer for the processing of personal data. It is voluntary for those who visit the web sites to provide personal information regarding services such as receiving newsletters and using the sharing and tip services. The treatment basis is the consent of the individual, unless otherwise specified.

1. Web analytics and cookies (cookies)

As an important part of the effort to create a user-friendly website, we look at the user pattern of those who visit the site. To analyze the information, we use the Google Analytics analysis tool.Google Analytics uses cookies (small text files that the site stores on the user's computer), which registers the users' IP address and provides information about the individual user's online movements. Examples of what the statistics give us answers to are; how many people visit different pages, how long the visit lasts, what websites users come from and what browsers are used. None of the cookies allow us to link information about your use of the site to you as an individual.The information collected by Google Analytics is stored on Google servers in the U.S.. The information received is subject to the Google Privacy Policy.An IP address is defined as a personal information because it can be traced back to a particular hardware and thus to an individual. We use Google Analytics's tracking code to anonymize the IP address before the information is stored and processed by Google. Thus, the stored IP address can not be used to identify the individual user.

2. Search

If the webpage has search function, it stores information about what keywords users use in Google Analytics. The purpose of the storage is to improve our information service. The search usage pattern is stored in aggregate form. Only the keyword is saved and they can not be linked to other information about the users, such as the IP addresses.

3. Share / Tips service

The "Share with others" feature can be used to forward links to the site by email, or to share the content of social networking. Tips for tips are not logged with us, but only used to add the tips to the community. However, we can not guarantee that the online community does not log this information. All such services should therefore be used wisely. If you use the email feature, we only use the provided email addresses to resend the message without any form of storage.

4. Newsletter

The website can send out newsletters by email if you have registered to receive this. In order for us to be able to send e-mail, you must register an e-mail address. Mailchimp is the data processor for the newsletter. The e-mail address is stored in a separate database, not shared with others and deleted when you unsubscribe. The e-mail address will also be deleted if we receive feedback that it is not active.

5. Registration, form

The website may have a form for registration, contact form or other form. These forms are available to the public to perform the tasks they are supposed to do.Registration form is for visitors to sign up or register.Contact form is for visitors to easily send a message to the website's contact person.We ask for the name of the sender and contact information for this. Personal information we receive is not used for purposes other than responding to the inquiry.The form is sent as email via Mailgun as a third party solution. The entire submission will be stored at Mailgun for 24 hours. Between 24 hours and 30 days, only mailheader is stored before the submission is deleted after 30 days. The reason for this storage is to confirm whether emails are sent from the website and forwarded to the correct recipient.Once the email is received by the recipient, it is up to the recipient to determine the data processing needs of the email.

6. Page and service functionality

Cookies are used in the operation and presentation of data from websites. Such cookies may contain language code information for languages ​​selected by the user. There may be cookies with information supporting the load balancing of the system, ensuring all users the best possible experience. For services that require login or search, cookies can be used to ensure that the service presents data to the right recipient.